Gasoline containing organic boronphosphorus additive



United States Patent O 3,158,451 GASGLINE CONTAINLNG URGANHC BQRGN-PHOSIHORUS ADDITIVIE Richmond T. Bell, Grayslfie, 113., assignor to Thelfure Oil Company, Chicago, TEL, a corporation of Qhio No Drawing. FiiedAug. 4, 1958, Ser. No. 753,087 10 Claims. (Cl. 44-69) This inventionrelates to new and useful improvements in gasoline compositions and moreparticularly to a gas line containing a small amount of aboron-phosphoruscontaining additive in an amount sutficient to reducespark-plug and other deposits in the combustion area and mitigate thedeleterious effects of such deposits, reduce octane-requirementincrease, increase the life of exhaust valves, and modify combustionarea deposits to mitigate the deleterious effects of such deposits.

Modern high-compression engines require fuels which are much superior tothose in use only a few years ago. Modern premium gasolines arespecially compounded to utilize hydrocarbon components having highoctane numbers are usually formulated with lead tetraethyl, or otherantiknock agents, to produce a fuel composition having a very highoctane rating. It has been found, however, that the additives Which areused in modern gasoline compositions contribute to the formation ofdeposits in gasoline engines which result in uncontrolled combustion,octane-requirement increase, and spark-plug fouling. To combat theseundesirable effects, a variety of additives have been used in gasolinesto mitigate or eliminate certain of these deleterious efiects. However,since a variety of undesired conditions are involved, a number ofdifferent additives have previously been required to mitigate saidconditions.

It is therefore one object of this invention to provide a superiorgasoline composition by incorporating therein a small amount of ahydrocarbon-soluble organic compound of phosphorus and boron.

Other objects of this invention will become apparent from time to timethroughout the specification and claims as hereinafter related.

This invention consists of a new and improved gasoline compositionproduced by incorporating in gasoline an additive consisting of ahydrocarbon-soluble, nonpyrophoric organic compound of phosphorus andboron. The additive is incorporated in the gasoline in a concentrationvarying from 0.0001 to 0.2% with a concentration of 0.001 to 0.1% beingpreferred. Additive compounds which are useful in accordance with thisinvention have the general empirical formula B P l-I R in Which R is a C-C hydrocarbyl radical, in and n are small integers, x is a smallinteger or zero, y is a small integer, and x+y is equal to the freevalences of B and P. Classes of compounds which fall within this formulainclude hydrocarbyl-substituted phosphine-boranes,hydrocarbyl-substituted phosphinoboranes, and polymers thereof, andhydrocarbyl derivatives of phosphonium borohydride. In these compounds,the hydrocarbyl substituents may be located on either the boron orphosphorus atom or both. When a gasoline composition is prepared usingone of the additive compounds of this invention, it has superiorantiknock properties, substantially reduced tendency toward theaccumulation of combustion-area deposits, including spark-plugs, andgreatly inhibits the deleterious effects of lead-containing enginedeposits, viz, uncontrolled combustions including rumble, startingknock, pre-ignition, after-running, etc., and minimizes octanerequirement increase (the increase in octane number required by anengine to avoid knocking upon accumulation of deposits in the combustionarea.

While the additives of this invention may be used with gasoiinescontaining no other additives, the principal commercial use of theadditives is in leaded gasoline compositions. The term leaded gasolinecompositions is used herein in its generally accepted technical andcommercial sense, viz., a gasoline containing lead tetraethyl and ascavenger such as ethylene dibromide, ethylene dichloride, or mixturesthereof. A premium-leaded gasoline which may be used as the base fuelfor the gasoline composition of this invention consists of a blend ofgasoline components from one or more of the following processes:straight distillation of crude oil, catalytic cracking, thermalcracking, isomerization, alkylation, polymerization, reforming,hydrogenation, etc., e.g., a blend of v. of gasoline from fluidcatalytic cracking (also referred to as FCC) and 20% v. ofgasoline-range alkylate. To prepare a typical premium gasoline, there isadded to a blended gasoline as just described 1.0-3.5 ml. per gallon ofcommercial tetraethyl lead fluid (a typical composition being 61.48 wt.percent tetraethyl lead, 17.86 wt. percent ethylene dibromide, 18.81 wt.percent ethylene dichloride, and 1.85 wt. percent kerosene, dye, andimpurities); l10 lb./ 1000 bbl. of an oxidation inhibitor, e.g., alkylphenylene diamines, and alkyl aminophenols, such asN-n-butylpara-aminophenol; 0.25-05 lb./1000 bbl. of a metal deactivator,e.g., salicylidene propane diamines, such asN,N'-disalicylidene-1,2-propanediamine; 0.05-0.5 lb./1000 bbl. of acorrosion inhibitor, e.g., t-amine salts of carboxylic acids, such asthe imidazoline salt of polymerized linoleic acid in an aromaticsolvent; 5-50 lb./1000 bbl. of an antiwear agent e.g., esters ofaromatic carboxylic acids, such as dibutyl phthalate, and 1% of ananti-icer (optional for winter fuel compositions), e.g., lower alcoholsor mixtures of alcohols and ethers, such as isopropanol,isopropanol-methanol mixture, isopropanol-isopropyl ether mixture. Theboronphosphorus-containing additive of this invention may be added to agasoline containing none of the above additives or containing any or allof the additives in any combination.

Additives which may be used in accordance with my invention arecompounds of boron, phosphorus, carbon, and hydrogen, i.e., hydrocarbylderivatives of boron and phosphorus hydrides, which are soluble inhydrocarbons to the extent of at least 0.0001%. These compounds includethe hydrocarbyl-substituted phosphine-boranes, hy-

drocarbyl-substituted phosphinoboranes, and polymers.

thereof, and hydrocarbyl derivatives of phosphonium borohydride, inwhich the hydrocarbyl substituents contain from 1 to 10 carbon atoms.The general empirical formula for compounds of this type is B P H R inwhich R is a C1-C hydrocarbyl radical, m and n are small integers, x iszero or a small integer, y is a small integer, and x+y satisfies thefree valences of B and P for the particular compound. Specific examplesof the classes of boron-phosphorus-containing compounds which may beused include the following:

(l) Phosphine-boranes of the formula xR P.xBR

where the Rs represent the same or different hydrocarbon radicals andone or more (but not all) of the Rs may be hydrogen, and the xs may bethe same or different integers.

(2) Phosphine-boranes, derived from diborane and higher boranes, of theformula BXHX+4JZPR3, where x is where the Rs represent the same ordifferent hydrocarbyl radicals, or one or more (but not all) of the Rsmay be hydrogen, and the is may be the same or different small integers,preferably l-4.

(3) Phosphinoboranes of the formula [R PBR [(R P) BR],,, [(R P) B] wherethe Rs represent the same or different hydrocarbyl radicals, and one ormore (but not all) of the Rs may be hydrogen, and x is a small integerincluding one. Some of the compounds covered EXAMPLE I A gasoline blendwas prepared consisting of 80% v. fluid catalytically cracked gasolineand 20% v. alkylate having added thereto 3 ml. tetraethyl lead fluid(i.e., tetraethyl lead plus ethylene dihromide and ethylene dichloride)per gallon of gasoline. A portion of this gasoline (7.5 gal.) wasprovided with 5 g. tri-n-butylphosphineborane, (C H P:BH producing aconcentration of 0.3 theory of phosphorus.

The gasoline containing the tri-n-butylphosphine-borane additive wasevaluated in a one-cylinder COT test-engine. In each test run, theengine was operated continuously under conditions tending to producemaximum deposits until fouling of the spark plug occurred and the lengthof time of the run before fouling was noted. The test engine wasoperated for 40 hours without any sign of spark plug fouling, at whichtime the fuel was exhausted. A similar run was made with the gasolineblend without the tri-nhutylphosphine-borane additive and the sparkplugs were fouled in 20 hours (average of 3 runs). The gasolinecontaining the tri-n-butylphosphine-borane additive, not only mitigatesspark-plug fouling, but also reduces uncontrolled combustion andsubstantially reduces the increase in octane requirement of an engine,i.e., substantially inhibits octane requirement increase. It is thusseen that the tri-n-butylphosphine-borane additive is a multipurposeadditive for inhibiting spark-plug fouling, uncontrolled combustion, andoctane requirement increase.

EXAMPLE II A number of gasoline compositions are prepared using bothleaded and unleaded gasoline containing various boronphosphoruscompounds as additives. These compositions are shown in Table 1.

duced effectiveness per unit of compound added at high levels. Theadditives of this invention are very effective for the purposesindicated when present in gasoline, either leaded or unleaded, inconcentrations of 0.0001 to 0.2 wt. percent, with concentrations in therange of 0.001 to 0.1 Wt. percent being preferred.

Some of the compounds covered by the aforementioned class arepyrophoric, and hence are impractical for commercial utilization. Forexample, dimethylphosphine tri methylborane and dimethylphosphinedimethylborane are spontaneously inflammable in air, and hold littleinterest as commercial gasoline additives. Others, such as the trimersand tetramers of dialkylphosphinoboranes and the trimers ofdialkylphosphinodialkylbcranes, are not only non-pyrophoric andtractable in open air, but are exceptionally stable thermally. Compoundswith character istics such as these are preferred for the motor fuelcompositions of this invention. It is to be further noted, however, thateven the compounds which are pyrophoric are operative for the purposesof this invention, though inconvenient to use. Some of these compoundswhich are pyrophoric in concentrated or pure form are not pyrophoricwhen dissolved in gasoline in the very low concentrations used in thisinvention.

While I have described my invention fully and completely as required bythe patent statutes with special emphasis upon several preferredembodiments thereof, I wish it understood that Within the scope of theappended claims, this invention may be practiced otherwise than asspecifically described.

What is claimed is:

1. A gasoline containing an antiknock quantity of tetraalkyl lead and asmall amount, suflicient to suppress preignition, of an organic boronandphosphorus-containing compound having the general formula:

wherein n is a value selected from the group consisting of 0 and 1 and mis a value taken from the group consisting of 3, l and 0, when n is l, mbeing selected from the group consisting of 0 and 1, when n is 0, inbeing 3; wherein R is selected from the class consisting of hydrogen andalkyl radicals, at least one of said R group representing Table IGasoline Leaded (3 ml. Additive (0.005% w. of phosphorus) TEL/gal.)

8O 20 FCC Alk late Methylphosphine-borane [CHaHsPZBHz].

/ o- L "Zn". Dimethylphosphine-borane [(GHMHP BEE].

FCC SO/QLETOC/Isopentane o 60140 Straight Disti no /Allrylat.e 70l3gsRetormate/Alkylate o 'Irimethylphosphine-borane [(OHmP: BB3].Tetramethylphosphoniumborohydrido [(CHmPBHQ. Tetraniethyl phosphoniunltetramethyl porane [P(C:I3)4B {CHM}, Dimethylphosphlnedimethylborane[(6.53) 2B1: BH(CH.-,)z]. Phosphinodimethylborane polymers[HzPB(CHs)2]:. Mcthylphosphinoborane polymers ICHaPHBHZh.

Dimethyl hospliinoboraue trimer [(CHK)2PBHE]3. Dimethylphosphinoboranetetramer [(CHQ)PBH2]4, Phosphinomethylborane polymers lHgPBfiCfiah.

. Methylphosphinodimethylborane [CH3HPB(CE3)2].

Dimethylphosphinoclimethylbnrane trimer [(CHQZPMCHQQJK.Dimethylphosphinomethylborane polymers [(CBQZPBHC- lillx.

When any of the fuel compositions set forth in Table I are used in theCOT test engine, the rate of spark-plug fouling is found to be decreasedby 25 to or more. Likewise, when the fuel compositions set forth inTable I are used in an automotive engine over an extended period, octanerequirement increase is effectively mitigated. It is also to be notedthat certain of the hydrocarbyl-substituted boron-phosphorous additive,such as the dimethylphosphinodimethylborane trimer, provides someincrease in octane rating of the fuel as Well as mitigating octanerequirement increase, reducing uncontrolled combustion, and reducingspark-plug fouling. Because of the exceptional effectiveness of theseadditives, only very small con-- ical and the remaining radicals are ofthe group consisting of hydrogen and (D -C hydrocarbyl radicals.

4. A leaded gasoline containing 0.0001-02 wt. percent of a compound ofthe formula B H .nPR, where x is 5 2 to 10, w is 1 to 4, and R is of thegroup consisting of hydrogen and C -C hydrocarbyl radicals.

5. A leaded gasoline containing 00001-02 wt. percent oftributylphosphine-borane.

6. A leaded gasoline containing of dialkylphosphine-borane.

7. A leaded gasoline containing 00001-02 wt. percent of the trimer of adialkylphosphinoborane, [R PBH where R is a C C alkyl radical.

8. A leaded gasoline containing 00001-02 wt. percent of the tetramer ofdialkylphosphinoborane, [R PBl-l h, where R is a C -C alkyl radical.

9. A leaded gasoline containing 0.0001-02 wt. percent of the trimer ofdialkylphosphinodialkylborane,

0.000l0.2 wt. percent [R PBR h where R is a C -C alkyl radical.

10. A leaded gasoline containing 0.000l0.2 wt. percent of (CH PBHReferences Gited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Chemical Reviews, vol. 58, No. 1, February 1958, StabilityRelationships Among Analogous Molecular Addition Compounds of Group IIIElements, by Stone, pages 101-129.

1. A GASOLINE CONTAINING AN ANTIKNOCK QUANTITY OF TETRAALKYL LEAD AND ASMALL AMOUNT, SUFFICIENT TO SUPPRESS PREIGNITION, OF AN ORGANIC BORON-AND PHOSPHORUS-CONTAINING COMPOUND HAVING THE GENERAL FORMULA: